Efficacy of midodrine for neurogenic orthostatic hypotension.
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Adrenergic alpha-Agonists↗
Biomedical subjects
I Berlin
Publications and source records attributed to I Berlin.
Effects of past history of major depression on smoking characteristics, monoamine oxidase-A and -B activities and withdrawal symptoms in dependent smokers.
Past history of major depression is more common in smokers than in non-smokers. We have shown in a previous study that lifetime prevalence of major depression is higher in dependent smokers and they have lower monoamine oxidase-A and -B activities than non-smokers. Because several studies have found an association between MAO-B activity and depression we analysed data of these smokers to assess whether past history of major depression is associated with reduced monoamine oxidase activities (A and B) or not. Further, we tried to characterize smokers with past history of major depression and its effect on withdrawal symptoms. The data of 88 dependent smokers (Fagerström Tolerance Questionnaire score > or = 6 and smoking > or = 20 cigarettes/day) who participated in a smoking cessation study were analysed. Smokers with past history of major depression but without current illness did not differ in demographic and smoking characteristics from smokers without past history of major depression. Smokers with past history of major depression were mainly women and had lower body mass index. Adjusted for gender and body mass index dependent smokers with or without past history of depression had similar MAO-A and MAO-B activities but smokers with past history of major depression had significantly lower resting plasma norepinephrine levels. Smokers with past history of depression had not significantly higher ratings for depression (Montgomery-Asberg Depression Rating Scales) and anxiety (Hamilton Anxiety Scales) and smoking cessation did not exacerbate these ratings (assessed up to 3 months) and none had depressive episode during the postcessation period up to one year. Past history of depression was associated with higher scores on 'expressed sadness' and 'depressive mood'. Abstinent smokers with past history of depression had significantly higher ratings in one of the seven ratings of a 6 months period for craving (day 28), anxiety (day 7) and total withdrawal symptom score (day 7) when compared to those who had no past history of major depression. It is concluded that (i) past history of major depression is more frequent in female smokers; (ii) smokers with past history of depression may have more intense withdrawal symptoms (craving and anxiety) at some time after cessation: and (iii) past history of depression does not affect monoamine oxidase activities, therefore, reduced monoamine oxidase activities found in previous studies are possibly characteristic features of smoking.
Adult↗
Phobic symptoms, particularly the fear of blood and injury, are associated with poor glycemic control in type I diabetic adults.
OBJECTIVE: To investigate the presence of psychiatric disorders and symptoms in type I diabetic patients and to identify those that may influence metabolic control as assessed by GHb levels. RESEARCH DESIGN AND METHODS: This was a cross-sectional study. One hundred and two consecutive patients with type I diabetes who were regular outpatient visitors of a diabetology department were evaluated. The psychiatric assessments included self-rating questionnaires (General Health Questionnaire and Fear Questionnaire) and observer-rating questionnaires (Montgomery-Asberg Depression Rating Scale [MADRS] and Mini International Interview). Diabetic characteristics were assessed by a structured interview. The observer was blind to the diabetic characteristics of the patients. RESULTS: Type I diabetic patients with GHb levels > or = 8% had higher psychological distress, scored significantly higher for symptoms of agoraphobia and for fear of blood and injury, had substantially higher levels of anxiety-depression, and performed significantly fewer blood glucose measurements per day. They did not differ in MADRS score from patients with GHb levels < 8%. Multivariate analysis showed that GHb was positively associated with the total score of phobic symptoms and the level of anxiety-depression and inversely associated with the number of daily blood glucose measurements. These factors explained 41% of the variance of GHb. The inverse relationship between GHb and the number of blood glucose measurements per day was mainly influenced by the fear of blood and injury. Patients with high scores for the fear of blood and injury performed fewer blood glucose measurements and had poorer glycemic control; conversely, subjects without fear of blood and injury performed more daily blood glucose measurements and had better glycemic control. CONCLUSIONS: Phobic symptoms are frequent in patients with type I diabetes. The intensity of phobic symptoms and anxiety-depression negatively influences metabolic control. Increased fear of blood and injury may lead some patients to perform few home blood glucose measurements and may result in poorer glycemic control. This suggests that, by decreasing the fear of blood, injury, and injection, metabolic control may be improved.
Adolescent↗
[Comparison between effects of morning and evening administration of effervescent calcium carbasalate (equivalent of 160 mg aspirin) on the gastroduodenal mucosa in healthy volunteers].
The aim of this randomised, cross-over trial was to compare the gastroduodenal tolerability and anti-aggregating effect of effervescent calcium carbasalate (ECC equivalent to 160 mg aspirin) given once daily either in the morning or in the evening. Twelve healthy volunteers received calcium carbasalate for 2 periods of 5 days (21 days of wash-out between the 2 periods). The principal criterion was the gastroduodenal tolerability assessed by the total number of lesions at upper gastro-intestinal endoscopy. The same treatment-blinded endoscopist performed all evaluations. Efficacy was evaluated by thromboxane B2 measurement and collagen-induced platelet aggregation tests. No difference was observed between morning and evening administration of ECC on gastroduodenal tolerability and platelet agregation. ECC was very well tolerated as assessed by upper gastrointestinal endoscopy and almost totally inhibited platelet aggregation.
Adult↗
Effects of befloxatone, a reversible selective monoamine oxidase-A inhibitor, on psychomotor function and memory in healthy subjects.
Befloxatone is a new reversible and selective monoamine oxidase (MAO-A) inhibitor that has been shown to have antidepressant activity in various animal models. To assess the effects of single oral doses of befloxatone (5, 10, and 20 mg) on psychomotor performance and memory, a randomized, double-blind, five-way, crossover study with both placebo and amitriptyline (50 mg) was carried out in 15 healthy male volunteers. Psychomotor and cognitive functions were evaluated using both objective measures, including Critical Flicker Frequency (CFF), Choice Reaction Time (CRT), Digit Symbol Substitution Test (DSST), and a picture memory test and subjective measures, including Visual Analog Scales (VAS) and Addiction Research Center Inventory (ARCI), before and 2, 4, and 8 hours after administration. Pupil diameter was recorded by videopupillography. Single doses of befloxatone from 5 to 20 mg did not result in any detrimental effects on skilled performance and memory. In contrast, amitriptyline significantly impaired arousal (CFF), speed of reaction (CRT), information processing (DSST) and long-term memory (delayed free recall of pictures) and produced subjective sedation from 2 to 8 hours after administration. At the doses studied amitriptyline induced miosis but befloxatone did not modify pupil diameter. There was no evidence in this study to suggest that befloxatone, at the doses studied, has any sedative or amnesic effects in healthy subjects.
Adult↗
Initial monoamine oxidase-A inhibition by moclobemide does not predict the therapeutic response in patients with major depression. A double blind, randomized study.
It is generally accepted that the clinical efficacy of monoamine oxidase inhibitors (MAOI) is related to inhibition of this enzyme. In order to evaluate the predictive ability of monoamine oxidase-A inhibition for therapeutic efficacy, the start of treatment effects of moclobemide, a selective, reversible monoamine oxidase-A inhibitor, on plasma concentrations of monoamines and monoamine metabolites were determined. The plasma levels of 3,4-dihydroxyphenylglycol (DHPG, deaminated metabolite of noradrenaline), 5-hydroxyindoleacetic acid (5-HIAA, deaminated metabolite of serotonin), 3,4-dihydroxyphenylacetic acid and homovanillic acid (DOPAC and HVA, deaminated metabolites of dopamine), L-dihydroxyphenylalanine (L-dopa) and noradrenaline were investigated and related to treatment outcome. This was a randomized double blind parallel group study in 47 patients with criteria of major depression according to DSM III R. Moclobemide 300 mg/day, 450 mg/day or 600 mg/day was administered continuously for 6 weeks. Plasma concentrations of monoamine metabolites and monoamines were determined just before treatment by moclobemide, 4 h after the first dose, 24 h after the first dose, before the first dose on day 7, and 4 h after the first dose, on day 7. Each moclobemide dose improved depression as measured by MADRS (Montgomery-Asberg Depression Rating scale) but there was no difference between the three doses. Moclobemide dose-dependently reduced plasma concentration of DHPG, L-dopa and HVA. No dose-dependent treatment effect was observed for plasma 5-HIAA, noradrenaline and DOPAC. The clinical outcome as defined by the final MADRS score was not related to any start of treatment changes in plasma monoamine metabolites reflecting inhibition of MAO-A. It is concluded that monoamine oxidase-A inhibition at the beginning of the treatment does not predict clinical outcome.
3,4-Dihydroxyphenylacetic Acid↗
[Treatment with selective and reversible monoamine oxidase inhibitors in depressed patients: is there a biological effect proportional to the dose?].
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Antidepressive Agents↗
Monoamine oxidase A and B activities in heavy smokers.
There is a strong association between depression and smoking. Because monoamine oxidase (MAO) inhibition leads to antidepressant effect and in vitro studies have shown that cigarette smoke inhibits MAO activity, it is conceivable that smoking may have an antidepressant effect, if smokers have reduced MAO activity. Therefore, we assessed platelet MAO-B activity and plasma concentration of catecholamine metabolites reflecting MAO-A activity in heavy dependent smokers and nonsmokers matched for sociodemographic characteristics. Platelet MAO-B activity, plasma 3,4-dihydroxyphenylglycol, plasma 3,4-dihydroxyphenylacetic acid, and plasma 3,4-dihydroxyphenylalanine concentrations were significantly lower in smokers than in nonsmokers, whereas plasma norepinephrine did not differ. Significantly more smokers reported previous history of depression, manic episode, panic attack, agoraphobia, and simple phobia. Smokers had higher scores (p < 0.001) on the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hamilton Anxiety Scales. It is concluded that the activities of both forms of the MAO are reduced in heavy dependent smokers.
3,4-Dihydroxyphenylacetic Acid↗
Beta-adrenoceptor agonists do not stimulate daytime melatonin secretion in healthy subjects. A double blind placebo controlled study.
Noradrenergic stimulation of pineal beta-adrenoceptors results in melatonin secretion. To investigate beta-adrenoceptor mediated plasma melatonin responses in humans, ritodrine, salbutamol (beta 2-adrenoceptor agonists) and dobutamine (beta 1-adrenoceptor agonist) were infused from 0900 to 1200 h to 8 healthy subjects (four men and four women) in a double blind, crossover, placebo controlled study. Ritodrine and salbutamol significantly increased plasma cyclic AMP and decreased serum potassium concentrations indicating the presence of beta 2-adrenoceptor stimulation. Dobutamine substantially increased systolic blood pressure corresponding to its beta 1-adrenoceptor agonist propriety. However, neither beta 2- nor beta 1-adrenoceptor stimulation modified plasma melatonin concentration. These results show that beta-adrenoceptor agonists do not increase daytime plasma melatonin concentration.
Adrenergic beta-Agonists↗
Pressor effect of oral tyramine during treatment with befloxatone, a new reversible monoamine oxidase-A inhibitor, in healthy subjects.
The interaction between tyramine and befloxatone, a new selective, reversible monoamine oxidase-A (MAO-A) inhibitor, was studied in a single-blind, parallel-group study in 30 healthy male volunteers whose fasting tyramine 30 dose (Tyr30) was 400 or 600 mg. Each subject completed a placebo run-in period followed by a befloxatone period. Befloxatone was given in repeated doses according to one of three regimens: befloxatone 20 mg once daily at the end of a meal rich in tyramine or befloxatone 10 or 20 mg twice daily 2 hours before a meal rich in tyramine. Subjects were given increasing daily doses of tyramine mixed with the meal, until a systolic blood pressure increase of at least 30 mm Hg was achieved (Tyr30). The mean Tyr30 decreased from 1220 mg (range, 600-1800 mg) during placebo to 290 mg (range, 150-500 mg) during befloxatone 20 mg once daily, 250 mg (range, 100-300) during befloxatone 10 mg twice daily, and 155 mg (range, 100-250 mg) during befloxatone 20 mg twice daily; corresponding to a potentiation factor of 5.2-, 6.5-, and 7.9-fold, respectively. The extent and the duration of the systolic blood pressure increase did not significantly differ between the placebo and the befloxatone regimens, except for a longer duration with the 20-mg twice daily regimen. These results are similar to those reported with the therapeutic dosage of other selective MAO-A inhibitors. They suggest that there would be little risk of hypertensive crisis in patients treated in clinical studies with befloxatone, and thus dietary restrictions appear to be unnecessary when the drug is given in a regimen of up to 20-mg once daily after meals.
Adult↗
A reversible monoamine oxidase A inhibitor (moclobemide) facilitates smoking cessation and abstinence in heavy, dependent smokers.
OBJECTIVE: To assess the effectiveness of moclobemide on smoking cessation and abstinence in heavy, dependent smokers. There is a strong association between smoking and depression, especially in dependent smokers. It was hypothesized that smoking is a self-medication to treat depression. Cigarette smoke has monoamine oxidase (MAO)-inhibitory properties, and smokers have lower MAO activity than non-smokers. METHODS: We used a randomized, double-blind, placebo-controlled parallel-group study. Placebo or moclobemide, 400 mg/day for 2 months and 200 mg/day during the third month, was given. Main outcome measures were self-reported and biochemically verified (plasma cotinine levels, < 20 ng/ml) abstinence rate. Secondary outcome measures were withdrawal symptoms, Montgomery-Asberg Depression Rating Scale, Hamilton anxiety rating scores, platelet MAO-B activity, and plasma dihydroxyphenylglycol as a measure of MAO-A activity. RESULTS: Eighty-eight smokers were randomized to receive moclobemide (n = 44) or placebo (n = 44). The continuous self-reported abstinence rate was higher with moclobemide than with placebo (intention-to-treat analysis until the end point, 6 months: p < 0.05; until the end of follow-up, 1 year: p = 0.09). The abstinence rate according to plasma cotinine levels showed a trend to effectiveness of moclobemide (end point: p = 0.13; follow-up: p = 0.12). Platelet MAO-B activity increased after smoking cessation but without a significant difference. Plasma dihydroxyphenylglycol levels did not change in the placebo group but decreased dose dependently in the moclobemide group. No difference occurred for withdrawal symptoms, Montgomery-Asberg Depression Rating Scale, and Hamilton anxiety scores. Cessation of moclobemide had no adverse effect. More subjects reported insomnia with moclobemide (n = 16) than with placebo (n = 3). CONCLUSION: In this preliminary study, the reversible, selective MAO inhibitor moclobemide facilitated smoking cessation in highly dependent smokers. Further studies with substantially more smokers are needed to evaluate the role of MAO inhibitors in smoking cessation and abstinence in smokers with high nicotine dependence.
Adult↗
Evaluation of the alpha 2-adrenoceptor blocking properties of buspirone and ipsapirone in healthy subjects. Relationship with the plasma concentration of the common metabolite 1-(2-pyrimidinyl)-piperazine.
1. Because the 5-HT1A agonist anxiolytic azapirones have a common alpha 2-adrenoceptor antagonist metabolite, 1-(2-pyrimidinyl)-piperazine (1PP), we measured central and peripheral alpha 2-adrenoceptor dependent responses before and after intravenous administration of 0.15 mg clonidine when healthy subjects were taking buspirone (30 mg day-1 for 4 days and 10 mg on day 5), ipsapirone (15 mg day-1 for 4 days and 5 mg on day 5) or placebo. 2. Clonidine decreased blood pressure, heart rate, oral body temperature, salivary excretion, plasma noradrenaline, 3,4-dihydroxyphenylglycol (DHPG) concentrations, increased plasma growth hormone but did not modify plasma insulin and C-peptide concentrations. Treatments tended to modify only the effect of clonidine on growth hormone (P = 0.07). 3. The azapirones reduced clonidine induced prolongation of choice reaction time (P = 0.015) and tended to antagonise clonidine induced fall in critical flicker fusion frequency (P = 0.066). 4. Only buspirone reduced total reaction time and increased critical flicker fusion threshold measured 12 h after the evening dose and these effects were correlated with the residual plasma 1PP concentration which was higher on buspirone than on ipsapirone (2.76 micrograms l-1, 95% CI:1.3-4.22 vs 0.65 microgram l-1, 95% CI: 0.32-0.98, P = 0.006). 5. Mean AUC of the 1PP plasma concentrations after the last dose of treatments were 3.7 times greater with buspirone than with ipsapirone (P = 0.0011). The AUC ipsapirone/AUC 1PP ratio was 6.45 and the AUC buspirone/AUC 1PP ratio was 0.076.(ABSTRACT TRUNCATED AT 250 WORDS)
Adrenergic alpha-Antagonists↗
Reduction of hyperglycemia after oral glucose load by the new alpha 2-adrenergic receptor antagonist SL 84.0418 in healthy subjects.
OBJECTIVE: To assess the antihyperglycemic activity of a new peripherally acting alpha 2-adrenergic receptor antagonist, SL 84.0418 in healthy volunteers METHODS: This was a randomized, double-blind crossover study. The effects of 10, 50, and 100 mg SL 84.0418 on blood glucose, plasma insulin, C-peptide, glucagon, epinephrine, and norepinephrine were investigated in comparison with placebo and 5 mg glipizide before and after an oral glucose challenge (75 gm). RESULTS: Peak blood glucose and area under the blood-glucose curve were dose-dependently reduced by SL 84.0418; the extent of this reduction was similar with 100 mg SL 84.0418 and glipizide. Glipizide but not SL 84.0418 decreased nadir blood glucose. Plasma insulin and C-peptide were increased by glipizide but not by SL 84.0418. Treatments did not modify plasma glucagon. Plasma epinephrine increased during glipizide treatment and plasma norepinephrine increased during treatment with 50 and 100 mg SL 84.0418. Systolic and diastolic blood pressure were moderately enhanced by 50 and 100 mg SL 84.0418. Adverse effects reflecting alpha 2-adrenergic receptor blockade occurred more frequently with 100 mg SL 84.0418. The adverse effect profile of 50 mg SL 84.0418 was not different from that observed with glipizide. CONCLUSION: The alpha 2-adrenergic receptor antagonist SL 84.0418 dose dependently reduced the increase in blood glucose after glucose load without modification of plasma insulin. It may represent an alternative to sulfonylureas in the treatment of non-insulin-dependent diabetes mellitus. Further studies are needed to assess its efficacy and tolerability in non-insulin-dependent patients.
Administration, Oral↗
Suspected postprandial hypoglycemia is associated with beta-adrenergic hypersensitivity and emotional distress.
Suspected postprandial (reactive or idiopathic) hypoglycemia is characterized by predominantly adrenergic symptoms appearing after meals rich in carbohydrates and by their rare association with low blood glucose level (< 2.77 mmol/L). We studied heart rate, blood pressure, plasma insulin, C-peptide, and catecholamine responses during a 5-h oral glucose tolerance test in eight patients with suspected postprandial hypoglycemia and eight age-, sex-, and body mass index-matched healthy controls. We also evaluated beta-adrenergic sensitivity by using the isoproterenol sensitivity test. Psychological profile was assessed by the Symptom Checklist (SCL-90R) self-report symptom inventory. Patients with suspected postprandial hypoglycemia had higher beta-adrenergic sensitivity (defined as the dose of isoproterenol required to increase the resting heart rate by 25 beats/min) than controls (mean +/- SEM, 0.8 +/- 0.13 vs. 1.86 +/- 0.25 microgram isoproterenol; P = 0.002). After administration of glucose (75 g) blood glucose, plasma C-peptide, plasma epinephrine, and plasma norepinephrine responses were identical in the two groups, but plasma insulin was higher in the patients (group effect, P = 0.02; group by time interaction, P = 0.0001). Both heart rate and systolic blood pressure were significantly higher (but remained in the normal range) after glucose administration in patients with suspected postprandial hypoglycemia than in controls (group by time interactions, P = 0.004 and 0.0007, respectively). After glucose intake, seven patients had symptoms (palpitations, headache, tremor, generalized sweating, hunger, dizziness, sweating of the palms, flush, nausea, and fatigue), whereas in the control group, one subject reported flush and another palpitations, tremor, and hunger. Analysis of the SCL-90R questionnaire revealed that patients had emotional distress and significantly higher anxiety, somatization, depression, and obsessive-compulsive scores than controls. We may conclude that patients with suspected postprandial hypoglycemia have normal glucose tolerance, increased beta-adrenergic sensitivity, and emotional distress.
Adult↗
Prazosin, diuretics, and glucose intolerance.
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Blood Glucose↗
Beta-adrenoceptor blockade potentiates acute exercise-induced release of atrial natriuretic peptide by increasing atrial diameter in normotensive healthy subjects.
The role of atrial distension and/or adrenergic mechanisms in the regulation of atrial natriuretic peptide (ANP) secretion, plasma immunoreactive ANP, norepinephrine (NE), epinephrine (E) and left atrial diameter at rest, during and after graded bicycle exercise has been studies in 8 healthy male subjects after single doses of placebo, tertatolol 5 mg (a non-selective beta-adrenoceptor blocker), prazosin 1 mg (an alpha 1-adrenoceptor antagonist) and their combination. Systolic and diastolic left atrial diameters were measured before, during and just after exercise by bidimensional echocardiography. Exercise caused an increase in plasma ANP, which was greater after tertatolol alone, and tertatolol plus prazosin, than after placebo or prazosin alone; the mean area under the plasma ANP concentration curve was increased by 35% after tertatolol alone, by 45% after tertatolol and prazosin compared to placebo, and by 82% and 94%, respectively when compared to prazosin alone. The rise in plasma ANP was more marked during the post-exercise period: 80% after tertatolol alone, 67% after tertatolol and prazosin compared to placebo, and 133% and 115%, respectively, compared to prazosin alone. The rise in plasma ANP was accompanied by an increase in both the systolic and diastolic atrial diameter, which was also significantly greater after tertatolol alone and the combination than placebo, or after prazosin alone. beta-Adrenoceptor blockade alone did not affect the plasma catecholamine concentrations, but the exercise-induced increase in plasma norepinephrine was significantly potentiated by prazosin and by prazosin plus tertatolol, and that of plasma epinephrine by the drug combination.(ABSTRACT TRUNCATED AT 250 WORDS)
Adrenergic beta-Antagonists↗
Is it dexfenfluramine or weight loss that reduces blood pressure and noradrenergic activity in obese patients?
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Blood Pressure↗